Chemical characteristics and colorimetric properties of non-centrifugal cane sugar (“panela”) obtained via different processing technologies

Abstract

Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and granulation, and also via a novel spray-drying powdering process without additives, were assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as colour parameters. As expected, sucrose was the predominant sugar (91.9–95.5%), followed by glucose (2.9–4.6%), and fructose (1.6–3.7%). Total phenolic content was between 0.4 and 0.6% and total flavonoid content into the range of 0.2–0.4%. Six phenolic acids were found in all NCS samples: protocatechuic acid (0.36–0.94 µg/100 g), vanillic acid (0.70–1.45 µg/100 g), chlorogenic acid (2.08–3.82 µg/100 g), syringic acid (1.08–2.80 µg/100 g), p-coumaric acid (0.69–1.35 µg/100 g), and ferulic acid (0.50–0.95 µg/100 g). The thermal treatment under high temperatures required in the production of granulated products was related with darker colours and changes in phenol and flavonoid contents. In contrast, spray drying generates clearer products, but with slightly less phenol and flavonoid contents.